How much power?

[Tomas Wallin]

Hi all,

Anyone have an estimate on how much power/torque and rpm my rotating assy would take?



The engine specs:
Block: Merlin II 509ci
Crank: Callies 4" stroke
Rods: Manley H-Beam
Pistons: JE blower pistons (757F) 4.5" Bore
Piston rings: Total seal TNT gapless top
Cam: Marine Kinetics Hyd roller
242º/250º @ .050" / .646"/646" lift valve / 112LSA
Wot RPM: 5800rpm
Heads: GM 188 ported chambers (ARP studs)
Head gaskets: FelPro MLS
C/R: 8.3
Valves: 1.88/2.25
Valve Springs: ISKY 8205PLUS
Rockers: Jesel Comp Series 1.7
Intake: BDS Blower intake
Intercooler: Superchiller
Blower: BDS 8-71
Boost: 8PSI (6.1% overdrive)
Carbs: 2x Holley 9022 800cfm
Jetting: 74/89 2.5PV Boost referenced (for the moment)
Ignition: MSD 6
Distributor: MSD 84891 Crab cap
Exhaust: Stainless Marine Gen III with 4.5" dry tails
Fuel: 93octane
Fuel system: Pickup tube ID: 5/8" / AN-10 from PU to A-1000 pump / AN-8 to fuel regulator / AN-8 to the fuel block and hard tubes to the carbs / AN-8 return with fuel cooler to the fuel filter. It is steady through the rpms.
Fuel pressure: 8-9PSI

[Mrhorsepower1]

1000 - 1050 HP would be safe

[Tomas Wallin]

1000 - 1050 HP would be safe

Thanks Dean!

And the follow up question... How much would it be possible to get out of GM 088 heads and the rest of the setup with changing the boost and possibly the cam and running 93 or 94 octane.


Perhaps Mr Bob Madara would like to chime in since you made the present cam?! :seeya:

[Tomas Wallin]

Thanks Dean!

And the follow up question... How much would it be possible to get out of GM 088 heads and the rest of the setup with changing the boost and cam and running 93 or 94 octane.


Perhaps Mr Bob Madara would like to chime in since you made the present cam?! :seeya:

TTT:seeya:

[rockfish71]

The 088 heads are good and even better with a little port matching up everthing they have a very good 325 cfm runner alot of people think aftermarket.. it's got to be better not aways you need the best for what your doing alot of engines here are only spinning 5700 or less and putting on all the biggest flowing everything and getting very sh!ty performance you have to optmize the airflow for the rpms your running and you will see lot's of good performance. when I state good performance I mean a storge pull from idle to wot.... not just wot

[Tomas Wallin]

Hey Rockfish,

Thanks for your reply, you're definately correct. It's not the best parts that works best - it's the best parts for the application that works best.

Would it be possible to get to 900HP with just adding more boost and retuning the carbs or will the increased boost cause detonation before I get to the 900 mark? On 93 octane of course. My dynoguy was a bit disappointed that I didn't have more than 8PSI since he thought I would get 900 without any problems - but I'm not all that convinced of it...

Is there a way to calc how much every added PSI of boost will add to the HP (as long as everything works fine without detonation etc). I guess I would better get a knock sensor if I would go that route...

[PatriYacht]

Because you have low compression and an intercooler, I would think it would be safe to increase boost to 10 lbs. You're getting 50-60 hp per 2 lbs. of boost already so that's about how much more I would expect from the pulley change. The GM heads flow poorly compared to any of the new aftermarket heads. Changing to a set of properly set up Iron Eagles would probably get you to 900 hp. Good luck.

[Geronimo36]

900 hp on Iron heads?

[Tomas Wallin]

Yeah! :26: But I will keep my 088's...

We'll see what the economy says later on, if I will bring it to the dyno once again and use the whole day to tune instead of messing around with things that wouldn't work the way they should (like last time) :ack2:

[PatriYacht]

I just assumed that you were boating in salt water and would want to keep running iron heads.

[Geronimo36]

I dunno folks... I'd like to hear from Mrhorsepower but I don't know if you could "reliably" make 900hp with a 509" and iron heads, even with an intercooler on 93 octane. Maybe on race gas...but why. Whaddya think Dean?

[Tomas Wallin]

I dunno folks... I'd like to hear from Mrhorsepower but I don't know if you could "reliably" make 900hp with a 509" and iron heads, even with an intercooler on 93 octane. Maybe on race gas...but why. Whaddya think Dean?
Well, I don't know for sure. It would be very interesting to hear what the engine gurus has to say about it, and as you said - why.

[Chris]

I can't imagine 088's flowing enough to support that much horsepower- especially on the exhaust side. Plus the iron heads lose the thermal benefit of the aluminum version, inviting preignition- even with a chiller.

Close to 2hp/cid? That's pushing it.

[Tomas Wallin]

I can't imagine 088's flowing enough to support that much horsepower- especially on the exhaust side. Plus the iron heads lose the thermal benefit of the aluminum version, inviting preignition- even with a chiller.

Close to 2hp/cid? That's pushing it.

Here's what the heads in question look like. They are also lightely port matched to the intake and exhaust.

The chambers is close to 120cc, that's about 2 more than the original 118.

[Chris]

Thge head bolt is in the way on the exhaust- there's just not enough material to open them up enough to flow the kind of flows you'd need to make those sort of numbers. The exhaust ports are raised on all the aluminum heads- to lessen the effect of that hard bend on flow.

And the iron head doesn't have near the thermal efficiency- which leads to detonation. That should be worth 75+ hp.

My guess is Dean was referencing how much HP the bottom end would handle.

[Tomas Wallin]

Thge head bolt is in the way on the exhaust- there's just not enough material to open them up enough to flow the kind of flows you'd need to make those sort of numbers. The exhaust ports are raised on all the aluminum heads- to lessen the effect of that hard bend on flow.

And the iron head doesn't have near the thermal efficiency- which leads to detonation. That should be worth 75+ hp.

My guess is Dean was referencing how much HP the bottom end would handle.

Yes Dean was refering to the bottom end.

I'm at 825HP@5800 and 815ft-lbs@4000 with 8PSI today.

[mdgperf]

Sounds like you got some good power from that combo,I think you would need to add cubes and better heads for reliable hp in the 900hp range on pump fuel,a solid roller could possibly add some hp but reliabilty could suffer,i know the cam companys are working on some different solid grinds and better lifters,could make solid rollers a better option in the future

[Tomas Wallin]

Sounds like you got some good power from that combo,I think you would need to add cubes and better heads for reliable hp in the 900hp range on pump fuel,a solid roller could possibly add some hp but reliabilty could suffer,i know the cam companys are working on some different solid grinds and better lifters,could make solid rollers a better option in the future

Yes, the bottom end is your recipe.:sifone:

I really like the combo as it is now but would like to optimize everything to get the absolute most out of it and still be reliable.

Do you remember what crankshaft it has. I couldn't find any proper serial# on it. Just Callies Stealth 39175 and Stealth is some special metal treatment as far as I have found out. You told me back then that the crank was the one better than DragonSlayer?!

[AGITATOR]

used to run that combo on my american offshore it made 890 hp at 6000 rpm and 850 ft of torque with a flat torque curve it was a good combo we ran 8 psi boost twim 900 cfm carbs non intercooled 32 deg timing 14 deg curve all in at 2500 rpm

[Tomas Wallin]

used to run that combo on my american offshore it made 890 hp at 6000 rpm and 850 ft of torque with a flat torque curve it was a good combo we ran 8 psi boost twim 900 cfm carbs non intercooled 32 deg timing 14 deg curve all in at 2500 rpm
Did you have GM Iron heads and pump gas on that engine?

[Chris]

The other thing you have to be wary of is engine builder and dyno operator adjustments on dyno testing. The term "corrected horsepower" can sometimes tell the whole story. RMBuilder (Bob Madara) has done some writing before on this topic. I have seen myself some correction factors that pushed the numbers on a dyno test far beyond reality. Sometimes it's due to an engine builder pushing his own numbers upward to make things look better, sometimes it's a dyno operator looking to make a customer feel better about their dyno session and the cost.

In addition, a max number on a dyno sheet doesn't come close to telling the whole story. Boats need big, fat midrange torque curves. Lots and lots of times, guys with lower horsepower engines win races. Simply because they're out-accelerating the guys with the big numbers.

[phragle]

SMP you can never have enough

[Tomas Wallin]

The other thing you have to be wary of is engine builder and dyno operator adjustments on dyno testing. The term "corrected horsepower" can sometimes tell the whole story. RMBuilder (Bob Madara) has done some writing before on this topic. I have seen myself some correction factors that pushed the numbers on a dyno test far beyond reality. Sometimes it's due to an engine builder pushing his own numbers upward to make things look better, sometimes it's a dyno operator looking to make a customer feel better about their dyno session and the cost.

In addition, a max number on a dyno sheet doesn't come close to telling the whole story. Boats need big, fat midrange torque curves. Lots and lots of times, guys with lower horsepower engines win races. Simply because they're out-accelerating the guys with the big numbers.

Yes of course! the dyno that I dynoed on is supposed to be one of the more accurate ones around, but you never know I suppose. That's why I posted the dyno sheets.

I wouldn't mind having a few more foot-pounds either, it's not the HP I'm after really - just the ability to go faster :sifone: :p

[Chris]

It's actually not the dyno, it's the operator. The "correction factors" are an area that sometimes are fudged. Raw data is "adjusted" for external conditions- air density, etc.

On your engines, I can't help but believe that a set of good aluminum heads would give you more on top and fatten up the middle nicely. Blowers compensate for alot of sins with heads, but there are limits.

[Chris]

This is an excellent tool for analyzing different head attributes.

http://users.erols.com/srweiss/tablehdc.htm#BBChevy

The things to look for beyond port CC's are-

-How well do they flow at partial lift?

-How does the relationship between volume and flow velocity look?

-What is the intake/exhaust ratio?

On a blower, you need more exhaust flow relative to intake flow. Forced induction increases charge density- a port will flow the same at atmospheric pressure as it will at atm+ so you get more fuel/air regardless of flow characteristics. So, you need higher exhaust flow. The blower won't have any effect on gases exiting from the engine.

Take a look at the AFR 315CNC head- relative to flow vs. velocity and int/exh ratios. This head works amazingly well on a motor like yours- looking at its capabilities on this chart relative to others is a good clue as to why.

[Tomas Wallin]

It's actually not the dyno, it's the operator. The "correction factors" are an area that sometimes are fudged. Raw data is "adjusted" for external conditions- air density, etc.

On your engines, I can't help but believe that a set of good aluminum heads would give you more on top and fatten up the middle nicely. Blowers compensate for alot of sins with heads, but there are limits.

That's what I meant :)

Alu heads would definately make things alot easier, but in my case it's all about optimizing what I've already got. :)

[Mrhorsepower1]

900 hp on Iron heads?

Frank I have built 468's SC with GM heads ported that make 850 HP and a 540 Merlin headed package that makes 975 HP.

[Mrhorsepower1]

Thge head bolt is in the way on the exhaust- there's just not enough material to open them up enough to flow the kind of flows you'd need to make those sort of numbers. The exhaust ports are raised on all the aluminum heads- to lessen the effect of that hard bend on flow.

And the iron head doesn't have near the thermal efficiency- which leads to detonation. That should be worth 75+ hp.

My guess is Dean was referencing how much HP the bottom end would handle.

Yes Chris , I was answering Thomas's question. How much power would the rotating kit would handle safely.

[AGITATOR]

yes on pump gas 93 with torco lead accelrator booster one qt for 15 gallons and i ran it to death and it ran great

[Chris]

What kind of $$ to make a set of 088's breathe?

[Mrhorsepower1]

What kind of $$ to make a set of 088's breathe?

The situation you run into now a day Chris, is by the time you perform all the machine work, porting , and component pricing for a bit more money you can buy a set of Dart Pro 1 or equal cylinder heads and bolt on more power. The 468 I was referencing to was built 20 years ago before all these nice parts were available.

[Chris]

That's what I figured. Good benchwork by a pro that knows what he's doing is expensive.

[Geronimo36]

Frank I have built 468's SC with GM heads ported that make 850 HP and a 540 Merlin headed package that makes 975 HP.

Thanks Dean. Is that on 91-93 Octane?

[Geronimo36]

yes on pump gas 93 with torco lead accelrator booster one qt for 15 gallons and i ran it to death and it ran great

What was the final octane after the torco?

I'm not trying to poke holes, I'm just saying on pump gas with such small cubes I'd think it would be hard to make 900 hp reliably on pump gas (91-93 octane). I could be completely wrong, so don't mind me! :) I just think that if it were easy, everyone would be doing it. :drool5:

[PatriYacht]

Depends on your definition of reliable. Smitty aka Arcticfriends found that leakdown after 150 hrs was pretty poor at that boost level. Set up and tune has to be correct also. We're lucky that we have all of that water to use for cooling. Just use a restricter instead of a thermostat and jet rich enough to keep the piston tops and oil from overheating.

[PatriYacht]

A member here, Ben Perfected is making 800 hp with a 502 naturally asperated single carb. I think he built them to the old B class rules. It does take a few more rpm though.

[MikeyFIN]

Here's what the heads in question look like. They are also lightely port matched to the intake and exhaust.

The chambers is close to 120cc, that's about 2 more than the original 118.


They vary all the way up to 122cc, depends a lot on the deck thickness and that´s one of the reasons we call GM original heads for Grusian Motors heads.
The key in heads are Velocity not necessarily top flow even with a boosted engine.
If I vere you I´d got with the Dart Big Iron heads ...the have a raised exhaust port and that´s the Achilles heel on them original heads.
I´ve done a few boat motors with those heads and Nowadays replace every 990 or 088 head with these if it´s a seawater cooled boat.

http://www.dartheads.com/products/heads/chevy-heads/bbc-heads/bbc-iron-heads/bbc-iron-eagle-heads.html

It´s your choice to go with either 308/345cc heads.. I´d opt for 345´s in your case.

[Tomas Wallin]

They vary all the way up to 122cc, depends a lot on the deck thickness and that´s one of the reasons we call GM original heads for Grusian Motors heads.
The key in heads are Velocity not necessarily top flow even with a boosted engine.
If I vere you I´d got with the Dart Big Iron heads ...the have a raised exhaust port and that´s the Achilles heel on them original heads.
I´ve done a few boat motors with those heads and Nowadays replace every 990 or 088 head with these if it´s a seawater cooled boat.

http://www.dartheads.com/products/heads/chevy-heads/bbc-heads/bbc-iron-heads/bbc-iron-eagle-heads.html

It´s your choice to go with either 308/345cc heads.. I´d opt for 345´s in your case.

Yo Mikey:sifone:

The chambers on these heads are just about 120cc.

I'm not going to replace the heads, if I would there would be no problem in using aluminum ones since the water over here is more or less brackish.

I'm just trying to optimize the engine as it is, and the first step will be to optimize the boost and carbs.

[MikeyFIN]

I'm just trying to optimize the engine as it is, and the first step will be to optimize the boost and carbs.

the first step IMO would be pocket porting and optimizing the exhaust ports...:biggrinjester:

[Tomas Wallin]

Yes but then the first step would be to deassemble the engine... And that's not happening! It's not interesting - the interesting part is how much it's possible to get from what I've got today - ONLY with tuning.

[Geronimo36]

Depends on your definition of reliable. Smitty aka Arcticfriends found that leakdown after 150 hrs was pretty poor at that boost level. Set up and tune has to be correct also. We're lucky that we have all of that water to use for cooling. Just use a restricter instead of a thermostat and jet rich enough to keep the piston tops and oil from overheating.

I hear ya, it's all good. My definition of reliable is 250 hrs on rebuild for a blower motor and 500 hrs NA'ed (valves/springs @ 250 hrs). I guess it also depends what blower you're running whether it be roots, centrifical or whipple etc. The roots make a lot of heat and will shorten lifespan and be more prone to detonation. I hear the new whipple is making some serious HP on the 525hp.

[AGITATOR]

any dyno sheet should show that at 5650 rpm the hp and torque cross on the sheet if they dont they dyno's info are bogus and the fuel is at 100 oct with torco leaded booster at that mix

[HaxbySpeed]

any dyno sheet should show that at 5650 rpm the hp and torque cross on the sheet if they dont they dyno's info are bogus and the fuel is at 100 oct with torco leaded booster at that mix

You're about 400rpm off there chief.. :dupe: And it's a mathematical equation that I'm pretty sure isn't affected by octane... :03: :rolleyes:

[HaxbySpeed]

(Torque x Engine speed) / 5,252 = Horsepower :)

[Mrhorsepower1]

A member here, Ben Perfected is making 800 hp with a 502 naturally asperated single carb. I think he built them to the old B class rules. It does take a few more rpm though.

I had built about 5 race boats back in the "A" and "B" class days also. 510 cu.in , 9.5:1 compression, iron heads, single carb. wetsump oiling, 15.5 inch primary header tube length, and we made 810 horsepower @ 7000 rpm. The engine would run 7000 rpm all year long and never come out of the boat till after 14 races before freshen! :biggrinjester:

[PatriYacht]

Very impressive. :sifone:

[Trim'd Up]

I had built about 5 race boats back in the "A" and "B" class days also. 510 cu.in , 9.5:1 compression, iron heads, single carb. wetsump oiling, 15.5 inch primary header tube length, and we made 810 horsepower @ 7000 rpm. The engine would run 7000 rpm all year long and never come out of the boat till after 14 races before freshen! :biggrinjester:

So I should be able to easily make 800 with the 555 that you talked me into right? ;) I will be getting with you after the holidays to spend some money.

[Geronimo36]

I had built about 5 race boats back in the "A" and "B" class days also. 510 cu.in , 9.5:1 compression, iron heads, single carb. wetsump oiling, 15.5 inch primary header tube length, and we made 810 horsepower @ 7000 rpm. The engine would run 7000 rpm all year long and never come out of the boat till after 14 races before freshen! :biggrinjester:


Very cool!!!

I bet these 598's can make much more than the 800hp they currently do!!!:) http://www.seriousoffshore.com/forums/showthread.php?t=327&page=2

[Mrhorsepower1]

Some of the boats I am referencing to are the ex powerboat mag Larry Smith Scarab " Let It Roll", "Feel The Rush", "Traffic Light", and "Rum Runners" to name a few. I loved the classes!!

[stinger]

I had built about 5 race boats back in the "A" and "B" class days also. 510 cu.in , 9.5:1 compression, iron heads, single carb. wetsump oiling, 15.5 inch primary header tube length, and we made 810 horsepower @ 7000 rpm. The engine would run 7000 rpm all year long and never come out of the boat till after 14 races before freshen! :biggrinjester:

So what combo does this? most marine engines are lucky to get 1.1 hp per cube.Our was this more a drag motor type combo?

[AGITATOR]

i no oct does not have anything to do with it i was answering his other question but you are right on the curve i stand corrected

[AIR TIME]

DEANS been putting together a 572 intercooled 1071 hope to see 1050hp:sifone: and in the fall take my 670hp motor 509 and make it more like 750hp with his custom= cam/intake/ and I have the carb from him.its my p5 motor hope to get back into some racing after my knee heals and insurance says I can play. so this summer I want to break a 100 or the other leg trying:26:. those A class motors ran nice in those boats wish I meet you back in 95 when I started messing with my 502 merc.Dean helped the guy with a twin motor to mine that had troubles with his cam and other stuff and it ran good last fall so mike should put some hours on his 572 this summer .I just wished last year that he sent it to you Dean to inspect.Can wait for mine getting the bug.haa hah.

[MOBILEMERCMAN]

Some of the boats I am referencing to are the ex powerboat mag Larry Smith Scarab " Let It Roll", "Feel The Rush", "Traffic Light", and "Rum Runners" to name a few. I loved the classes!!

The good old days. As I remember A allowed 510" and B 460"